There is known a banknote verification device corresponding to patent No. RU2344481 (published 20 Jul. 2007, G07D7/12). The device has a linear light source and a linear sensor between which a banknote moves; a linear sensor registers the light emitted from the source and transmitted through the banknote. To provide a uniform illumination, there is used the Ulbricht cylinder with illumination devices (for example, light emitting diodes) as a light source and an additional imaging system. However, the efficiency of light transmission from the light sources to the banknote is less than 50%, and illumination intensity still tends to droop at the edges of the zone being registered. Low efficiency results from diffuse nature of the reflection in the Ulbricht cylinder and from a partial matching of the optical output of the cylinder with the optical input of the imaging system.
There is known the <<Banknote Identifier>> device in correspondence with invention application No. RU2007109222 (published 20 Sep. 2008, G06F1/00). This device includes the module of an optical radiation source; the above-mentioned module contains the definite number of packs of light emitting diodes with various wavelengths as well as the optical receiver module located on the opposite side of the banknote feed path and including the definite number of photodiodes between the banknote feed path and the module of the optical radiation source; in addition, the lens systems are placed between the feed path and the optical receiver module. According to this solution, each lens provides illumination of one round area of the banknote. Inspection is conducted in one or several banknote zones orientated in the direction of the banknote movement along the path. This ensures simplicity and cheapness of the device; but to conduct a quality verification of the banknote moving along the path, one needs information about light transmission through the whole surface of the banknote which may be obtained only with uniform illumination along its entire width. To meet this requirement (according to the known invention), the device needs a large number of light emitting diode packs and lenses; as a result, it loses its design simplicity and its cost rises.